Julie L Yee

Historical methyl mercury in San Francisco Bay

San Francisco Bay, California is considered a mercury-impaired watershed. Elevated concentrations of mercury are found in water and sediment as well as fish and estuarine birds. Sources of mercury to the watershed since 1845 include sediment-associated mercury from mercury mining, mercury losses from gold amalgamation activities in mines of the Sierra Nevada, aerial deposition of mercury from global and regional emissions to air, and the direct discharge of mercury to Bay waters associated with the urbanization and industrialization of the estuary. We assessed historical trends in mercury bioaccumulation by measuring mercury concentrations in feathers of the endangered California Ridgway’s rail (formerly California...

Categories: Data; Tags: California Ridgway's Rail, Feathers, Ice Cores, Lake Tahoe, Mercury, All tags... San Francisco Bay, Sediment, Structural Equation Model, USGS Science Data Catalog (SDC), Wyoming, Fewer tags

Annual California Sea Otter Census - 2020 Spring Census Summary

In light of the ongoing COVID-19 pandemic, the USGS and partners at the California Department of Fish and Wildlife, Monterey Bay Aquarium, and the U.S. Fish and Wildlife Service have decided to cancel this year's annual rangewide southern sea otter census. Normally, the census is conducted in May using a combination of ground and aerial survey counts. However, this year the COVID-related issues have led to unsurmountable logistical difficulties due to safety precautions and distancing requirements. The annual southern sea otter surveys, conducted cooperatively by scientists of the U.S. Geological Survey, California Department of Fish and Wildlife, Monterey Bay Aquarium, and U.S. Fish and Wildlife Service with...

Annual California Sea Otter Census: 2019 Extra Limit Observations Shapefile

The GIS shapefile Extra limit counts of southern sea otters 2019 is a point layer representing the locations of sea otter sightings that fall outside the officially recognized range of the southern sea otter (Enhydra lutris nereis) in mainland California. These data were collected during the spring 2019 range-wide census. The USGS range-wide sea otter census has been undertaken each year since 1982, using consistent methodology involving both ground-based and aerial-based counts. The spring census provides the primary basis for gauging population trends by State and Federal management agencies. Sea otter distribution in California (the mainland range) is considered to comprise a band of potential habitat stretching...

Categories: Data; Types: Downloadable, Map Service, OGC WFS Layer, OGC WMS Layer, Shapefile; Tags: California, Central California Coastal, Southern California Coastal, aerial counts, biogeography, All tags... biota, distribution, environment, mammals, ocean, range, sea otter census, sea otters, sea otters, shore counts, Fewer tags

Demographic model inputs and code, catchment area population estimates, and counterfactual (CIU) estimates for population growth for 23 focal bird species.

Renewable energy production can kill birds, but little is known about how it affects avian populations. We assessed vulnerability of populations for 23 priority bird species killed at wind and solar facilities in California, USA.

Categories: Data; Tags: California, Canada, Coastal California, Ecology, Energy Resources, All tags... Land Use Change, Mojave and Sonoran Desert, USGS Science Data Catalog (SDC), United States, Wildlife Biology, anthropogenic effects, biota, bird populations, birds, ecosystem management, environment, renewable energy, solar, wildlife biology, wildlife mortality, wind, wind energy, Fewer tags

Annual California Sea Otter Census: 2019 Census Summary Shapefile

The GIS shapefile Census_sum_2019 provides a standardized tool for examining spatial patterns in abundance and demographic trends of the southern sea otter (Enhydra lutris nereis), based on data collected during the spring 2019 range-wide census. The USGS spring range-wide sea otter census has been undertaken each year since 1982, using consistent methodology involving both ground-based and aerial-based counts. The spring census provides the primary basis for gauging population trends by State and Federal management agencies. This shapefile includes a series of summary statistics derived from the raw census data, including sea otter density (otters per square kilometer of habitat), linear density (otters per kilometer...

Categories: Data; Types: Downloadable, Map Service, OGC WFS Layer, OGC WMS Layer, Shapefile; Tags: California, Central California Coastal, Coast, Southern California Coastal, aerial counts, All tags... biogeography, biota, distribution, environment, mammals, ocean, range, sea otter census, sea otters, sea otters, shore counts, Fewer tags